C3 (Chaney Compacted Concrete) is Chaney Enterprises’ Roller Compacted Concrete (RCC) paving mix which has been specially formulated and optimized for strength and mix stability.
C3 has the same ingredients as conventional concrete but is pre-mixed at the plant then shipped in a dump truck and placed with equipment common to the asphalt industry at costs 20% to 30% lower.
Roller compacted concrete shares both properties of asphalt and concrete so it truly represents the best of both worlds delivering short and long-term value.
The appearance is very similar to the open graded look of asphalt, only it has a much lighter color that reduces the urban heat effect and decreases lighting needs by 30%.
For most applications, C3 will be the lowest initial cost of all paving options. Cost advantages will be most apparent when compared to single-lift asphalt pavements greater than 3” or any two-lift asphalt pavements. Initial cost comparisons will vary widely depending on many factors, but the cost savings will generally be between 5% and 25%.
Initial versus Lifecycle Costs for an average Commercial Parking Lot
While the initial cost of C3 is appealing, the real cost savings is in the long-term lifecycle:
C3 is extremely versatile and can be used in a number of ways for parking lots, industrial yards and roads depending on the project and goals of the owner.
There is a great deal of design help available for engineers. The National Ready Mix Concrete Association offers a Design Assistance Program (DAP) that is free if submitted through an association member such as Chaney Enterprises.
For parking lots, ACI 330.1-03, Specification for Unreinforced Concrete Parking Lots contains design charts to easily identify the section thickness. For road design, the American Concrete Pavement Association has made design software available called StreetPave available at: www.acpa.org/streetpave
Compressive strengths come in a wide range, but are typically between 4,000 to 10,000 psi and most commonly in the 5,000 to 7,000 psi range.
Construction of roller compacted concrete pavements is more similar to asphalt than it is to traditional concrete. Our mix is optimally designed for compaction and stability. It is pre-mixed at our plant and can travel up to an hour to the job site in a normal dump truck.
Placement can be done in a variety of methods ranging from graders to conventional asphalt pavers to high density pavers. The difference is in the initial compaction of the material. The better the initial compaction, the more uniform the surface will be. Small asphalt pavers will achieve an initial compaction of about 80% to 85% and will typically require two to three passes with a properly weighted roller. A high density paver may achieve more than 95% initial density and may or may not require additional roller compaction. C3 should be rolled until 96% compaction or better is achieved.
Once compaction is achieved, a quality curing compound MUST be applied such as Thinfilm 445 which is available at The Concrete Store.
Cracking occurs in all concrete. Joints direct cracking in a more aesthetically pleasing way. While joints are always optional, in C3 they are needed less. Cracking occurs at a greatly reduced rate and it is perfectly acceptable in some cases to let the C3 crack naturally. If joints are desired, they should be cut with an early entry saw at about half the rate of traditional concrete. For example, for 4.5 inches of C3 , the maximum joint spacing could be as much as 18’ to 20’.
While a 24 hour curing period is always recommended, once compaction is achieved, the pavement maybe immediately opened to limited, light traffic.
While C3 is more durable and will likely require less maintenance than conventional concrete, when maintenance issues do arise, the fix is typically the same. Patching and repairing can be done with either conventional concrete or C3 .
There are many examples nationally and regional of Roller Compacted Concrete (RCC). Here are just a few in our region.
Sycamore Street (Local Road)
Upper Nazareth Township, PA
The existing asphalt road required reconstruction. The projected costs for the asphalt reconstruction were between $99,000 and $116,000 for 1,728 square yards. The contractor proposed using RCC as the base for an asphalt topping. The final price was about $70,000 for a 30% to 40% cost savings.
The Concrete Store (Distribution Yard)
When our very own Concrete Store needed an inexpensive paving solution, we called an asphalt paver to place RCC. Sections of the storage yard required frequent repairs due to the heavy truck and forklift traffic in the yard. The quality of the job exceeded the warehouse manager’s expectations and saved the store a significant amount of money.
Staffordboro Boulevard Park & Ride (Parking Lot)
This pilot project for VDOT included complete reconstruction of the parking lot and small section of the northbound lanes on Staffordboro Boulevard. The RCC was placed and then covered with a thin layer of asphalt. VDOT deemed this a successful project and has continued to contract projects around the state.
Pennsylvania Power & Light (PPL)
PPL needed a solution that was cost effective and could handle the heavy traffic in the parking lot at their service center. Paving with RCC came in at $875,000 which was 27% cheaper than the cost of conventional concrete. RCC also came in lower than the bid for asphalt.
Over 1.5 million square yards of 5” and 7” RCC span this production plant located just outside Birmingham. The total plant size is 3.7 million square feet with an annual production of 340,000 vehicles and V-6 engines.
C. Steinweg RCC Pour
At 30,000 sq ft, the C. Steinweg Group had acquired a contract to store feed grain that prohibited the storage of it on an asphalt surface. Multiple concrete options were considered, but it was quickly realized that roller compacted concrete (RCC) would be the most economical solution.
James Monroe High School
Frustrated by frequently asphalt repairs in their parking lot, the maintenance staff at James Monroe High School in Fredericksburg, Virginia were looking for a better solution. After meeting with a local asphalt paver who was experienced in roller compacted concrete, it was decided that roller compacted concrete would be the most durable pavement. .
King George High School
King George, VA
After a medical emergency on the athletic fields of King George High School in Virginia, quick response vehicles were unable to navigate the soft ground of the dirt road leading to the playing fields.The entire 400 foot long path was paved in under two hours, open to emergency traffic immediately and general traffic the next morning.
Riddle Mine Site
The roadway into the Riddle Sand and Gravel operation supports about 300 to 400 trucks with sand and gravel each day. After years of abuse, the asphalt road could not hold up under the traffic strains. To complicate matters, this busy location operates six days a week and the one and only entrance road could not be out of commission for an extended period.